Bottlebrush Shield Lichen

LC - Least Concern

NNR - Unranked

not listed

Bottlebrush Shield Lichen is a common, widespread, typical shield lichen. It occurs in Europe, Asia, and North America. In the United States, it occurs in the east from Maine to New Jersey, west to Ohio and Minnesota, and south along the Appalachian Mountains to northern Georgia. It also occurs on the West Coast from northern Washington to central California. In Minnesota it is relatively common in the northeast and north-central regions, but it is mostly absent from the remainder of the state.

Bottlebrush Shield Lichen is found in deciduous and mixed forests, both primary forests, undisturbed by human activity, and secondary forests, cleared by human activity and regenerated. It grows mostly on bark on the trunks, branches, and twigs of trees, including relatively young trees. It also grows on rocks, stones, and pebbles. It rarely grows on moss.

The vegetative body (thallus) is leaf-like (foliose), widely spreading, stretched out flat, and divided into overlapping lobes. The lobes are solid, 1⁄32″ to 3 ⁄16″ (1 to 5 mm) wide, elongated, and closely appressed to the substrate. The color may be bluish gray, greenish gray, or whitish gray. The upper surface may be flat or pitted. It often develops tiny cracks or breaks, allowing the inner white filaments (hyphae) to extend to the surface, appearing like tiny pores. These pores, called pseudocyphellae, often join together, forming a white, net-like pattern on the surface. Asexual reproductive structures (isidia) are produced on the margins and on the surface of the thallus. The isidia are cylindrical and up to 1⁄64″ (.05 mm) tall. They are most dense in the central, older part of the thallus. Powdery reproductive granules (soredia) are not produced. The lower surface of the thallus is black. It is attached to the substrate by black, much branched, root-like structures (rhizines). The rhizine branches spread out at right angles (squarrose). This is the feature that gives the lichen its species epithet.

Reproductive structures (apothecia) may be present or absent. When present, they can be abundant. The apothecia are large, plate-like, and concave or flat. They may be pale and tan or yellowish tan, or medium and cinnamon brown.

Salted Shield Lichen (Parmelia saxatilis) rhizines are unbranched or forked.

Trees, rocks

Foliose

Deciduous and mixed forests

Trees and rocks

Sources

4, 24, 26, 29, 30, 81.

Common

This lichen was previously described as Parmelia saxatilis. It was separated from that species in 1971 based on the distinctive right-angle (squarrose) branching of the rhizines. Molecular phylogenetic studies published in 2004 confirmed the separation.

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Location: Cass County